TOIDS “Rule Breaker” center channel

Description

This is an unpublished design. Plans are available from TOIDS, and can be purchased here.

At the time of the customer’s request for assistance (October 2025) it was difficult to find the single full-range driver (tweeter position) in-stock. The customer contacted the manufacturer who had available inventory in-stock, even though it wasn’t listed for sale.

If you are looking at this design, and don’t see that driver available from retailers, the manufacturer may still have product available.

Recommendations:

This is intended as a budget design.

Capacitors: The two high-capacitance capacitors are specified in the design as electrolytics. Due to space limitations and the high capacitance (cost and size), that decision is understood. Someone wanting to avoid electrolytics could place the resulting large poly/film capacitors in the rear corners of the cabinet, where they would have adequate space. Bypass capacitors would be a more affordable way to supplement and improve upon standard electrolytics and are offered here as default.

Due to the small internal cabinet volume, If a builder had preferences for higher-tier components (larger non-electrolytic capacitors, larger gauge inductors) it would be acceptable to adjust for that internal volume by adding 1/2″ to 1″ of cabinet depth to the speaker design.

Inductors: The design calls for an iron-core inductor on the woofer circuit. Due to the reasonably low inductance value (low cost), an 18-gauge air-core inductor is offered here instead, by request of the customer. However, retaining use of the iron-core ($13 savings) would also be acceptable. If you have a preference for an iron-core or for a larger gauge are-core, please reach out by email and we can modify for you.

Resistors: We have kept it very simple here. High-Quality resistors are very affordable. There is only one resistor in the circuit. We are providing a GR Research branded 10 watt resistors ($4.00 each).

Wiring: The cabinet is fairly small. 5ft of each color is plenty for this design. We are also offering an option for 20ft of each color if you want to purchase discounted wire for an additional or future project.  Wire is priced at 20% discount.  You may also purchase the kit without our wire.

We do think our wiring is the best value available. It is a premium wire without the traditional markups. We offer 16ga solid strand, high-purity OFC, Polyethylene insulator, made in the USA.  Wire details are here.